Video game reviews of Xbox Live Arcade, PlayStation Store offerings

In this video game image released by Microsoft, a giant mech battles electronic monsters in a scene from " Trenched" (AP Photo/Microsoft)

Video-game publishers seem to believe their audience would rather risk sunburn than have fun in air-conditioned comfort, so you won’t find many major new games in stores during the summer. But that doesn’t mean there’s nothing new out there — and you don’t need to search any further than the online services Xbox Live Arcade and the PlayStation Store.

One studio that’s made a big impression in the download-only market is Double Fine Productions, led by industry legend Tim Schafer. Its new release is called “Trenched” (Microsoft, for Xbox 360, $15), and it’s a witty mash-up of the third-person shooter and tower defense genres.

You control a “trench,” a giant, walking mech that you can deck out with machine guns, cannons, grenade launchers and other weapons. You can also place a limited number of stationary turrets to help defend your territory. You’ll need all that to save Western civilization from the Tubes, an electronic menace bent on enslaving humanity.

“Trenched” isn’t as silly as Double Fine’s previous downloadable titles, “Costume Quest” and “Stacked,” though it does have some laugh-out-loud gags. (From a menu describing an olive paint job you can apply to your trench: “This paint is not actually made of olives. Please do not eat it.”) On the other hand, the game play is more expertly paced, smoothly ramping up the difficulty as it provides access to more powerful weapons. It’s a relatively short campaign, but the ability to join forces with up to three friends online boosts its replay value.

In “Half-Minute Hero: Super Mega Neo Climax” (Marvelous Entertainment, for Xbox 360, $10), you have just 30 seconds to stop a madman from unleashing Armageddon. Fail, and you can reset and try again. Succeed, and the credits roll — until you discover there’s another madman waiting in the next town over.

Over the course of more than 60 quests, “Half-Minute Hero” deftly parodies all the cliches and conventions of Japanese role-playing games like “Final Fantasy.” As someone who has spent hundreds of hours saving the world, I really got a kick out of saving two or three during a TV commercial break.

“Red Johnson’s Chronicles” (Lexis Numerique, for PlayStation 3, $13) is less frenetic but still absorbing. It’s a detective story laced with brainteasers, much like Nintendo’s Professor Layton games, but the mystery is more down-to-earth: Who killed a much-loathed street thug? It’s not a particularly surprising or rewarding case, and the end game — in which you have to answer about 50 multiple-choice questions to build an indictment — is a drag.

However, during the investigation you have to solve a few dozen puzzles of observation and logic. These challenges are generally clever, and a few are downright diabolical (but fair). “Red Johnson” is an odd beast, mixing noir atmospherics, Soviet-style graphics, a jazzy soundtrack and a protagonist who looks more hipster than gumshoe. But it delivers a satisfying set of puzzles for a good price.